Preferably, the density of the pulp fiber is 1-1.5 g/cm³(ii) a The fiber length of the paper pulp fiber is 3-12 mm, and the fiber diameter is 5-20 mu m.

Preferably, SiO in the perlite powder₂The content is more than or equal to 68 wt%; the true density of the perlite powder is 2.2-2.4 g/cm³(ii) a The heat conductivity coefficient of the perlite powder is 0.05-0.08W/m.k;

SiO in the floating bead₂The content is 50-65 wt%; the true density of the floating bead is 0.35-0.45 g/cm³(ii) a The floating bead guideThe thermal coefficient is 0.05-0.1W/m.k;

SiO in the hollow glass bead₂The content is more than or equal to 80 wt%; the true density of the hollow glass beads is 0.35-0.45 g/cm³(ii) a The heat conductivity coefficient of the hollow glass beads is 0.03-0.08W/m.k.

Preferably, Al in the kaolin₂O₃Content is more than or equal to 44.5wt%, Fe₂O₃The content is less than or equal to 0.85wt percent, and the water content is less than or equal to 1wt percent;

al in the Zhangzhou mud₂O₃Content is more than or equal to 35wt%, Fe₂O₃Content is less than or equal to 1.2wt%, TiO₂The content is less than or equal to 0.4wt percent, and the water content is less than or equal to 10wt percent.

Preferably, the binder is selected from inorganic binders and/or organic binders.

Preferably, the inorganic binder comprises sodium silicate and/or silica sol;

the organic binder comprises starch and/or cellulose.

Preferably, the heat-insulating coating comprises the following components in percentage by mass:

the invention provides a preparation method of the heat-insulating coating, which comprises the following steps:

mixing inorganic fiber, organic fiber, low-heat-conductivity filler, fire-resistant filler, bonding agent and water to obtain the heat-insulating coating.

The invention provides a heat-insulating coating which is formed by coating and drying the heat-insulating coating in the technical scheme.

Compared with the prior art, the invention provides a heat-insulating coating, a preparation method thereof and a heat-insulating coating. The heat-insulating coating provided by the invention is prepared from the following components in percentage by massThe meter comprises the following components: 5-30% of inorganic fiber; 0.5-5% of organic fiber; 10-30% of low-thermal-conductivity filler; 2-20% of a fire-resistant filler; 15-35% of a binding agent; 20-40% of water; the inorganic fibers are selected from one or more of rock wool fibers, aluminum silicate fibers and calcium magnesium silicate fibers; the organic fiber is paper pulp fiber; the low-heat-conductivity filler is one or more of perlite powder, expanded vermiculite powder, floating beads and hollow glass beads; the fire-resistant filler is selected from kaolin and/or Zhangzhou mud. The invention has the advantages that the component composition of the heat-insulating coating is optimally designed, and particularly, specific inorganic fibers, organic fibers and fillers are selected, so that the service performance of the coating in a high-temperature environment is obviously improved; after the heat-insulating coating is coated on the surface of the furnace lining of the kiln, the formed coating has low heat conductivity coefficient, high strength and no cracking at high temperature, can effectively protect the furnace lining from being eroded by the severe environment in the furnace, and prolongs the service life of the furnace lining. Experimental results show that the wet volume weight of the thermal insulation coating provided by the invention is 900-1500 kg/m³The volume weight after drying at normal temperature is 350-650 kg/m³(ii) a The compressive strength of a coating formed by coating and drying the heat-insulating coating is more than or equal to 1MPa, the shrinkage of a heating wire (1000 ℃ multiplied by 24h) is less than or equal to 3 percent, and the thermal conductivity coefficient at 1000 ℃ is less than or equal to 0.165W/m.k.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

the components of the heat-insulating coating provided by the invention comprise inorganic fibers, organic fibers, low-heat-conductivity filler and fire resistanceFiller, binder and water. Wherein the inorganic fiber is selected from one or more of rock wool fiber, aluminum silicate fiber and calcium magnesium silicate fiber; the rock wool fiber preferably meets the relevant requirements of national standard GBT 11835-2016; al in the aluminum silicate fiber₂O₃And SiO₂The total content of (B) is preferably not less than 97wt%, and the content of shot (particle diameter is more than 0.212mm) is preferably not more than 20 wt%; SiO in the calcium magnesium silicate fiber₂The content is preferably 55-66 wt%, the content of CaO is preferably 26-32 wt%, the content of MgO is preferably 4-7 wt%, and the content of slag balls (with the particle size larger than 0.212mm) is preferably less than or equal to 16 wt%. In the present invention, the content of the inorganic fiber in the thermal insulation coating is 5 to 30 wt%, specifically 5wt%, 6wt%, 7wt%, 8wt%, 9 wt%, 10wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, or 30 wt%.

In the heat-insulating coating provided by the invention, the organic fiber is pulp fiber; the density of the pulp fiber is preferably 1-1.5 g/cm³Specifically, it may be 1g/cm³、1.05g/cm³、1.1g/cm³、1.15g/cm³、1.2g/cm³、1.25g/cm³、1.3g/cm³、1.35g/cm³、1.36g/cm³、1.4g/cm³、1.45g/cm³Or 1.5g/cm³(ii) a The fiber length of the paper pulp fiber is preferably 3-12 mm, and specifically can be 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm or 12 mm; the fiber diameter of the pulp fiber is preferably 5-20 μm, and specifically can be 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm or 20 μm; the tensile strength of the pulp fiber is preferably more than or equal to 550 MPa. In the present invention, the content of the organic fiber in the thermal insulation coating is 0.5 to 5wt%, specifically 0.5 wt%, 0.7 wt%, 1wt%, 1.2wt%, 1.5 wt%, 1.7 wt%, 2wt%, 2.3 wt%, 2.5 wt%, 2.7 wt%, 3 wt%, 3.2 wt%, 3.5 wt%, 3.7 wt%, 4wt%, 4.2 wt%, 4.5wt%, 4.7 wt%, or 5 wt%.

In the bookIn the heat-insulating coating provided by the invention, the low-heat-conductivity filler is one or more of perlite powder, expanded vermiculite powder, floating beads and hollow glass beads; SiO in the perlite powder₂The content is preferably more than or equal to 68wt%, and the true density of the perlite powder is preferably 2.2-2.4 g/cm³The heat conductivity coefficient of the perlite powder is preferably 0.05-0.08W/m.k, the upper limit sieve of 20-60 meshes of the perlite powder is preferably not more than 2wt%, and the lower limit sieve of 60-80 meshes of the perlite powder is preferably not more than 2 wt%; SiO in the floating bead₂The content is preferably 50-65 wt%, and the true density of the floating bead is preferably 0.35-0.45 g/cm³Specifically, it may be 0.418g/cm³The thermal conductivity of the floating bead is preferably 0.05-0.1W/m.k, and specifically can be 0.08W/m.k; SiO in the hollow glass bead₂The content is preferably more than or equal to 80wt%, and the true density of the hollow glass bead is preferably 0.35-0.45 g/cm³Specifically, it may be 0.4g/cm³The heat conductivity coefficient of the hollow glass beads is preferably 0.03-0.08W/m.k, specifically 0.056W/m.k, and the particle size of the hollow glass beads is preferably 2-100 μm. In the present invention, the content of the low thermal conductive filler in the thermal insulation coating is 10 to 30 wt%, and specifically may be 10wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, or 30 wt%.

In the heat-insulating coating provided by the invention, kaolin and/or Zhangzhou mud are selected as the refractory fillers; al in the kaolin₂O₃The content is preferably 44.5wt% or more, Fe₂O₃The content is preferably less than or equal to 0.85wt%, and the water content is preferably less than or equal to 1 wt%; al in the Zhangzhou mud₂O₃The content is preferably not less than 35wt%, Fe₂O₃Preferably less than or equal to 1.2wt%, TiO₂The content is preferably less than or equal to 0.4wt%, the water content is preferably less than or equal to 10wt%, and the ignition loss is preferably less than or equal to 15 wt%. In the invention, the content of the fire-resistant filler in the heat-insulating coating is 2-20 wt%, specifically 2wt%, 3 wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9 wt%, 10wt%, 11 wt%, 12 wt%, 13 wt%,14, 15, 16, 17, 18, 19 or 20 wt%.

In the heat-insulating coating provided by the invention, the binding agent is preferably an inorganic binding agent and/or an organic binding agent; the inorganic binder preferably comprises sodium silicate and/or silica sol; the Baume degree (20 ℃) Be of the sodium silicate is preferably 45-55, and more preferably 49-52; na of the sodium silicate₂The content of O is preferably more than or equal to 12 wt%; SiO of the sodium silicate₂The content is preferably more than or equal to 28.5 wt%; the modulus of the sodium silicate is preferably 2-3M, and more preferably 2.2-2.5M; SiO of the silica sol₂The content is preferably 25 to 35wt%, more preferably 29 to 31 wt%; na of the silica sol₂The O content is preferably less than or equal to 0.4 wt%; the pH value of the silica sol is preferably 8.5-10; the viscosity of the silica sol at 25 ℃ is preferably less than or equal to 7 mPa.s; the colloid diameter of the silica sol is preferably 10-20 μm; the density of the silica sol is preferably 1-1.3 g/cm³More preferably 1.19 to 1.21g/cm³(ii) a The organic binder preferably comprises starch and/or cellulose; the starch is preferably mesh starch; the viscosity of the 5wt% concentration solution of starch is preferably more than or equal to 2000mPa.s at 25 ℃; the pH value of the 5wt% concentration solution of the starch is preferably 6-8; the degree of substitution of the starch is preferably more than or equal to 0.033; the sieving amount of the starch with a 100-mesh sieve is preferably more than or equal to 90 wt%; the viscosity of the 2wt% concentration solution of cellulose at 25 ℃ is preferably 5000-15000 mPa.s, more preferably 8000-10000 mPa.s; the pH value of the cellulose is preferably 6.5-8; the moisture content of the cellulose is preferably less than or equal to 10 wt%; the sodium content of the cellulose is preferably 6 to 10wt%, and more preferably 6.5 to 8.5 wt%. In the present invention, the content of the binder in the thermal insulation coating is 15 to 35wt%, specifically 15 wt%, 15.5 wt%, 16 wt%, 16.5 wt%, 17 wt%, 17.5 wt%, 18 wt%, 18.5 wt%, 19 wt%, 19.5 wt%, 20 wt%, 20.5 wt%, 21 wt%, 21.5 wt%, 22 wt%, 22.5 wt%, 23 wt%, 23.5 wt%, 24 wt%, 24.5 wt%, 25 wt%, 25.5 wt%, 26 wt%, 26.5 wt%, 27 wt%, 27.5 wt%, 28 wt%, 28.5 wt%, 29 wt%, 29.5 wt%, 30 wt%, 30.5 wt%, 31 wt%, 31.5 wt%, 32wt%, 32.5 wt%, 33 wt%, 33.5 wt%, 34 wt%34.5 wt% or 35 wt%. In the invention, the content of the inorganic binder in the insulating coating is preferably 15-30 wt%, and specifically may be 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, or 30 wt%; the content of the organic binder in the thermal insulation coating is preferably 0.5-5 wt%, and specifically may be 0.5 wt%, 1wt%, 1.5 wt%, 2wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4wt%, 4.5wt%, or 5 wt%.

In the heat-insulating coating provided by the invention, the content of water in the heat-insulating coating is preferably 20 to 40 wt%, and specifically may be 20 wt%, 20.5 wt%, 21 wt%, 21.5 wt%, 22 wt%, 22.5 wt%, 23 wt%, 23.5 wt%, 24 wt%, 24.5 wt%, 25 wt%, 25.5 wt%, 26 wt%, 26.5 wt%, 27 wt%, 27.5 wt%, 28 wt%, 28.5 wt%, 29 wt%, 29.5 wt%, 30 wt%, 30.5 wt%, 31 wt%, 31.5 wt%, 32wt%, 32.5 wt%, 33 wt%, 33.5 wt%, 34 wt%, 34.5 wt%, 35wt%, 35.5 wt%, 36 wt%, 36.5 wt%, 37 wt%, 37.5 wt%, 38 wt%, 38.5 wt%, 39 wt%, 39.5 wt%, or 40 wt%.

The invention also provides a preparation method of the heat-insulating coating, which comprises the following steps:

In the preparation method provided by the invention, the inorganic fiber, the organic fiber, the low-heat-conductivity filler, the fire-resistant filler, the bonding agent and the water are directly and uniformly mixed in proportion to obtain the heat-insulating coating provided by the invention.

The heat-insulating coating and the preparation method thereof provided by the invention have the advantages that the component composition of the heat-insulating coating is optimally designed, and particularly, specific inorganic fibers, organic fibers and fillers are selected, so that the service performance of the coating in a high-temperature environment is obviously improved; after the heat-insulating coating is coated on the surface of the furnace lining of the kiln, the formed coating has low heat conductivity coefficient, high strength and no cracking at high temperature, can effectively protect the furnace lining from being eroded by the severe environment in the furnace, and prolongs the service life of the furnace lining.

Experimental results show that the wet volume weight of the heat-insulating coating provided and prepared by the invention is 900-1500 kg/m³The volume weight after drying at normal temperature is 350-650 kg/m³(ii) a The compressive strength of a coating formed by coating and drying the heat-insulating coating is more than or equal to 1MPa, the shrinkage of a heating wire (1000 ℃ multiplied by 24h) is less than or equal to 3 percent, and the thermal conductivity coefficient at 1000 ℃ is less than or equal to 0.165W/m.k.

The invention also provides a heat-insulating coating which is formed by coating and drying the heat-insulating coating in the technical scheme. The heat-insulating coating provided by the invention is prepared from the heat-insulating coating provided by the invention, so that the coating has excellent performance (low heat conductivity coefficient, high strength and no cracking at high temperature) in a high-temperature environment, can effectively protect a furnace lining from being corroded by severe environment in a furnace, and prolongs the service life of the furnace lining.

Experimental results show that the compressive strength of the heat-insulating coating is more than or equal to 1MPa, the shrinkage of a heating wire (1000 ℃ multiplied by 24h) is less than or equal to 3 percent, and the thermal conductivity coefficient under the condition of 1000 ℃ is less than or equal to 0.165W/m.k.

For the sake of clarity, the following examples are given in detail.

In the following examples provided by the present invention, product information of the inorganic fibers used is shown in table 1:

TABLE 1 inorganic fibre information Table

In the following examples provided by the present invention, the product information of the pulp fibers used is shown in table 2:

TABLE 2 paper pulp fiber information Table

In the following examples provided by the present invention, the product information of the low thermal conductive filler used is shown in table 3:

TABLE 3 Low Heat conductivity Filler information sheet

In the following examples provided by the present invention, the product information of the fire-resistant filler used is shown in table 4:

table 4 fire-resistant filler information table

Name of raw materials	Ingredient (wt%)	Water content (wt%)	Loss of ignition (wt%)
				Shanxi Kaolin	Al₂O₃≥44.5；Fe₂O₃≤0.85	≤1.0	/
Zhangzhou mud	Al₂O₃≥35；Fe₂O₃≤1.2；TiO₂≤0.4	≤10	≤15

In the following examples provided by the present invention, the product information of the used sodium silicate (water glass) is shown in table 5:

TABLE 5 sodium silicate information Table

Categories	Five categories
		Baume (20 ℃) Be	49～52
Sodium oxide (wt%)	≥12.0
		Silicon dioxide (wt%)	≥28.5
Modulus (M)	2.2～2.5

In the following examples provided by the present invention, the product information of the silica sol used is shown in table 6:

TABLE 6 silica Sol information Table

In the following examples provided by the present invention, the product information of the starch used is shown in table 7:

TABLE 7 starch information Table

In the following examples provided by the present invention, the product information of the cellulose used is shown in table 8:

TABLE 8 cellulose information Table

Viscosity of 2wt% aqueous solution (mPa. s, 25 ℃ C.)	pH value	Water content (wt%)	Sodium content (wt%)
				8000～10000	6.5～8.0	≤10	6.5～8.5

Example 1

The heat-insulating coating comprises the following components in parts by mass: 15% of aluminum silicate fibers, 1% of pulp fibers, 20% of hollow glass beads, 7% of kaolin, 20% of silica sol, 2% of cellulose and 35% of tap water; and (3) uniformly mixing the raw materials in proportion to obtain the heat-insulating coating.

The heat-insulating coating prepared in the embodiment is detected, and the result is as follows: the wet bulk weight is 1100kg/m³(ii) a Volume weight after normal temperature drying is 500kg/m³(ii) a Compressive strength 1.25 MPa; the heating wire shrinks (1000 ℃ is multiplied by 24h) by 1.83 percent; the thermal conductivity coefficient is 0.79W/m.k at the hot surface of 200 ℃, 0.114W/m.k at the hot surface of 600 ℃, 0.132W/m.k at the hot surface of 800 ℃ and 0.152W/m.k at the hot surface of 1000 ℃.

Example 2

The heat-insulating coating comprises the following components in parts by mass: 10% of calcium magnesium silicate fiber, 1.5% of pulp fiber, 15% of floating bead, 15% of Zhangzhou mud, 25% of silica sol, 1.5% of cellulose and 32% of tap water; and (3) uniformly mixing the raw materials in proportion to obtain the heat-insulating coating.

The heat-insulating coating prepared in this example was tested, and the results were as follows: wet volume weight 1150kg/m³(ii) a Volume weight after normal temperature drying is 550kg/m³(ii) a The compressive strength is 1.6 MPa; heating wire shrinkage (1000 ℃ for 24h) is 1.7 percent; the thermal conductivity coefficient is 0.76W/m.k at the hot surface of 200 ℃, 0.115W/m.k at the hot surface of 600 ℃, 0.135W/m.k at the hot surface of 800 ℃ and 0.151W/m.k at the hot surface of 1000 ℃.

Example 3

The heat-insulating coating comprises the following components in parts by mass: 20% of rock wool fiber, 2% of paper pulp fiber, 20% of perlite, 5% of kaolin, 25% of water glass, 1.5% of starch and 26.5% of tap water; and (3) uniformly mixing the raw materials in proportion to obtain the heat-insulating coating.

The heat-insulating coating prepared in the embodiment is detected, and the result is as follows: wet bulk weight 1170kg/m³(ii) a Volume weight of 570kg/m after drying at normal temperature³(ii) a The compressive strength is 1.4 MPa; heating wire shrinkage (1000 ℃ for 24h) is 1.7 percent; thermal conductivity, hot face 200 ℃ of 0.74W/m.k, hot face 600 ℃ of 0.118W/m.k, hot face 800 ℃ of 0.137W/m.k, hot face 1000 ℃ of 0.150W/m.k.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and amendments can be made without departing from the principle of the present invention, and these modifications and amendments should also be considered as the protection scope of the present invention.

Claims

1. The heat-insulating coating is arranged on the surface of a furnace lining of a kiln and is formed by coating and drying a heat-insulating coating; the heat-insulating coating comprises the following components in percentage by mass:

5-30% of inorganic fiber;

0.5-5% of organic fiber;

10-30% of low-heat-conductivity filler;

2-20% of a fire-resistant filler;

15-35% of a binding agent;

20-40% of water;

the inorganic fiber is selected from rock wool fiber, aluminum silicate fiber or calcium magnesium silicate fiber;

the organic fiber is paper pulp fiber; the density of the paper pulp fiber is 1-1.5 g/cm³The fiber length is 3-12 mm, and the fiber diameter is 5-20 μm;

the low-heat-conductivity filler is selected from perlite powder, floating beads or hollow glass beads; SiO in the perlite powder₂The content is more than or equal to 68wt%, and the true density is 2.2-2.4 g/cm³The heat conductivity coefficient is 0.05-0.08W/m.k; SiO in the floating bead₂The content is 50-65 wt%, and the true density is 0.35-0.45 g/cm³The heat conductivity coefficient is 0.05-0.1W/m.k; SiO in the hollow glass bead₂The content is more than or equal to 80wt%, and the true density is 0.35-0.45 g/cm³The heat conductivity coefficient is 0.03-0.08W/m.k;

the fire-resistant filler is selected from kaolin or Zhangzhou mud;

the binding agent is selected from inorganic binding agent and/or organic binding agent; the inorganic binder is sodium silicate or silica sol, and the organic binder is starch or cellulose.

2. Thermal insulating coating according to claim 1, characterised in that the aluminium silicate fibres are Al₂O₃And SiO₂The total content of (A) is more than or equal to 97 wt%;

3. The thermal coating of claim 1, wherein Al in said kaolin is₂O₃Content is more than or equal to 44.5wt%, Fe₂O₃The content is less than or equal to 0.85wt percent, and the water content is less than or equal to 1wt percent;

4. The thermal insulation coating according to claim 1, wherein the thermal insulation coating comprises the following components in percentage by mass:

10-20% of inorganic fiber;

1-2% of organic fiber;

15-20% of low-heat-conductivity filler;

5-15% of fire-resistant filler;

20-25% of an inorganic binder;

1.5-2% of an organic binder;

26.5-35% of water.